Adherence

Subjective feelings of loneliness are robustly associated with poorer sleep quality (specifically subjective quality and daytime dysfunction) in young adults, independent of social isolation, psychopathology, and genetic/family confounds.

If you are feeling lonely, expect your sleep quality to suffer, specifically how rested you feel and your daytime energy, even if you get enough hours in bed. This is not just 'in your head' but a documented physiological response involving threat vigilance. Addressing the underlying social connection or cognitive perception of isolation may be more effective for sleep than standard sleep hygiene alone.